Horton

Re: pgsql: Document XLOG_INCLUDE_XID a little better

Dilip Kumar <dilipbalaut@gmail.com>

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From: Dilip Kumar <dilipbalaut@gmail.com>
To: Alvaro Herrera <alvherre@alvh.no-ip.org>
Cc: Amit Kapila <amit.kapila16@gmail.com>, Robert Haas <robertmhaas@gmail.com>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Date: 2021-10-02T10:46:31Z
Lists: pgsql-hackers

Attachments

On Fri, Oct 1, 2021 at 6:24 PM Alvaro Herrera <alvherre@alvh.no-ip.org> wrote:
>
> On 2021-Oct-01, Amit Kapila wrote:

> I think a straight standalone variable (probably a static boolean in
> xloginsert.c) might be less confusing.

I have written two patches, Approach1 is as you described using a
static boolean and Approach2 as a local variable to XLogAssembleRecord
as described by Amit, attached both of them for your reference.
IMHO, either of these approaches looks cleaner.

>
> ... so, reading the xact.c code again, TransactionState->assigned really
> means "whether the subXID-to-topXID association has been wal-logged",
> which is a completely different meaning from what the term 'assigned'
> means in all other comments in xact.c ... and I think the subroutine
> name MarkSubTransactionAssigned() is not a great choice either.

I have also renamed the variable and functions as per the actual usage.

-- 
Regards,
Dilip Kumar
EnterpriseDB: http://www.enterprisedb.com

Commits

  1. Move MarkCurrentTransactionIdLoggedIfAny() out of the critical section.

  2. Replace XLOG_INCLUDE_XID flag with a more localized flag.

  3. Document XLOG_INCLUDE_XID a little better

  4. Immediately WAL-log subtransaction and top-level XID association.